converted GrConfigConversionEffect to SkSL

Bug: skia:
Change-Id: If17cf0fc8b857d22f33a462a39a02bcddd15deda
Reviewed-on: https://skia-review.googlesource.com/55741
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
diff --git a/gn/sksl.gni b/gn/sksl.gni
index 65913e3..55e8bd2 100644
--- a/gn/sksl.gni
+++ b/gn/sksl.gni
@@ -29,6 +29,7 @@
   "$_src/effects/GrCircleBlurFragmentProcessor.fp",
   "$_src/gpu/effects/GrBlurredEdgeFragmentProcessor.fp",
   "$_src/gpu/effects/GrCircleEffect.fp",
+  "$_src/gpu/effects/GrConfigConversionEffect.fp",
   "$_src/gpu/effects/GrDitherEffect.fp",
   "$_src/gpu/effects/GrEllipseEffect.fp",
   "$_src/gpu/effects/GrSimpleTextureEffect.fp",